Time delay circuits are used to provide a predetermined propagation delay to signals. In many applications, the time delay introduced by the time delay circuit is particularly critical. Environmental conditions, such as temperature, greatly effect the propagation characteristics of the circuit components. One way to compensate for a change in component propagation characteristics is by manually changing the value of one of the components of the time delay circuit. Frequently, the circuit is inaccessible or the adjustment must be made with such rapidity that manual adjustment is not suitable. In certain situations, the time delay adjustment must be made automatically or accomplished by remote control. Further, various applications require different degrees of resolution; that is, varying adjustment increments are required.